砖基础顶面标高，用水准仪和尺量检查，偏差不得超过（）。
A、±5mm
B、±10mm
C、±15mm
参考答案：C
用所给词的适当形式填空。
1. Do you know _________(she) name?
2. He doesn't play sports. He only watches _________(they) on TV.
3. I have two _________(dictionary).
4. Do you like _________(tomato)?
5. Look! Those are Tim's _________(parent).
6. This is a photo of _________(Jim) family.
7. His father _________(have) a French car.
8. My book and my pen _________(be) on the dresser.
短路事故对电力系统有什么危害？
